Abstract: Formation of undesirable popcorn polymer on the walls of a reaction vessel during thermal dimerization of butadiene is prevented by coating the walls with a falling film of aqueous sodium nitrite solution.

Abstract: Phenol-aldehyde resins are prepared by condensing phenol with formaldehyde and isobutyraldehyde in the presence of an alkali. The resulting resins are particularly suited for manufacturing products such as fiberboard and chipboard.

Abstract: Molding compositions or masses comprising sand and a two-component binder system are prepared. These two-component binders consist essentially of 1) polyisocyanate and 2) a low molecular weight polymethylol produced by the controlled condensation of narrow mole ratios of acetone and formaldehyde under alkaline reaction conditions followed by acidification and removal of sufficient water to produce a minimum solid content of at least 95%. These molding compositions cure so fast that they may be taken off the mold five minutes after having been cured with an amine curing agent, and reach a substantial bending strength within minutes of curing compared to prior art compositions which achieve comparable bending strength only after a period of as long as one hour.

Abstract: Wood materials are prepared, characterised by improved resistance to hot water and by high weather resistance, by combining wood products with a phenol-aldehyde resin and alkylene carbonate hardener, the latter being incorporated in said resin as an aqueous formaldehyde solution.